The invention relates to a gas bag module for restraining a vehicle occupant. In particular, the invention relates to a gas bag module integrated in the steering wheel.
Gas bag modules are known, which in addition contain multifunctional keys, mounted from the exterior, for actuation of the telephone, the radio and the like. Here, these keys can be designed as combined operating- and display keys. Through the integration of light-emitting diodes, the symbols are also able to be read on nighttime journeys. The addition of multifunctional keys always involves the formation of a gap between the keys and the covering cap, more precisely its front wall, which is visible from the front face in the installed state. A great effort is required to keep the installation tolerances as small and uniform as possible. In spite of these disadvantages, there is a need to house additional information displays in the vehicle, because modern vehicles are equipped with increasing operating functions, so that it is difficult, in part, to house all the displays in the cockpit. It is endeavored to provide modules with a high-quality external appearance, in which the displays are integrated without a gap occurring between the displays and the remainder of the covering cap. The production of such a gas bag module, in particular the achieving of a sufficient stability of the covering cap is, however, a problem.
The invention provides a gas bag module which has a high-quality external appearance and into which the displays can be integrated.
This is achieved in a gas bag module which comprises a covering cap which is visible from the exterior in an installed state and covers an outlet opening for a gas bag. The module further comprises at least one display integrated in the covering cap and a lighting for the display provided on a rear face of the covering cap. The covering cap has a front wall visible from the exterior with a section covering the outlet opening, the section being integrally connected, i.e. in one piece, with a display section lying over the lighting. In the display section, the covering is constructed so as to be transparent or translucent. The display section is made of a first material component of the covering cap and the covering cap includes a second material component which has a carrier layer in the form of a cup. The base of the cup forms the section closing the outlet opening and the peripheral wall of which laterally delimits an accommodation space for the gas bag.
According to the invention, the covering cap extends as far as to over the light, i.e. it continues into the display and is constructed so as to be transparent or translucent in the region of the light. Through the construction in one piece, no gap is produced, so that a smooth visible front wall is presented to the occupant from the exterior. The display can either be arranged behind the front wall under the transparent or translucent region. Furthermore, however, the covering cap itself can also form the display, by the covering cap being transparent along lines to create a symbol, e.g. by the transparent section forming a xe2x80x9c+xe2x80x9d or xe2x80x9cxe2x88x92xe2x80x9d. Of course, a larger display field could also lie behind the transparent region, e.g. an illuminated LCD screen, which can provide various displays. The stability of the covering cap is, however, achieved through the support layer, and this only makes possible the transparent or translucent construction of the first material component. Through the cup-shaped construction of the support layer, the regions which are mainly stressed on opening of the covering cap, are stabilized namely to the side of the gas bag and in the direction outwards.
Preferably, the first material component is connected with the second material component in the region of the base and extends laterally beyond the border of the base and forms in this region the display section.
The transparent or translucent layer forms here the border of the front wall.
In the region of the display section, the covering cap preferably has, at least in these sections forming numbers or symbols, a smaller thickness, so that a greater transparency is achieved.
The previously mentioned possibility that the covering cap itself forms a display can be constructed such that the covering cap has a transparent/translucent layer with an external, impermeable covering layer which is partially not present, namely in the region of the display.
This covering layer can, for example, be subsequently removed from the exterior, e.g. by means of a laser. Alternatively, of course, the transparent layer could be partially covered on application of the opaque covering layer.
An advantageous covering layer is a lacquer which is adapted in terms of color and its surface with the rest of the interior.
The display, e.g. the symbols, can, however, already be introduced into the injection-mold for manufacture of the covering cap and can be coated with a thin translucent layer of lacquer.
Thermoplastic polyurethane or thermoplastic polymer, which are made by the injection-molding process into the covering cap, present themselves as materials for the transparent display section.
The transparent or translucent layer can form only a section of the front wall or else can extend across the entire front wall, which can offer advantages in terms of manufacturing technique.
The preferred embodiment makes provision that the illumination is situated outside the accommodation space, preferably separated from the accommodation space directly by the peripheral wall. Thereby, on its unfolding, the gas bag is prevented from scraping on the lighting of the display, and the lighting or the gas bag are prevented from being damaged. Through the peripheral wall, a three-dimensional separation of the accommodation space from the region with the lighting is achieved. Also, it can be ruled out that the lighting might be pulled along by the unfolding gas bag. For this, the front wall only tears open up to the transition of the front wall to the peripheral wall.